Electricity is essential to electronic devices, such as portable/wearable computer and communications systems, home appliances, entertainment systems, office equipment, industrial robots, server farms/data centers, telecommunications equipment, military systems, marine electronics, and the like. Monitoring the amount of current delivered to a system/load is critical for understanding, for example, the system's impact on battery life, safety decisions in over-current protection circuits, the system's health, and establishing system and subsystem power budgets/allowances.